Ington biags



UNITED STATES PATENT OFFICE.

JOHN H. W. BIGGS, OF LIVERPOOL, COUNTY OF LANCASTER, ENGLAND.

CENTRIFUGAL WASHING AND DRYING MACHINE.

SPECIFICATION forming part of Letters Patent No. 244,029, dated July 12, 1881,

Application filed January 6, 1881.

i To all whom it may concern Be it known that I, J OHN HOWARD WORTH- INGTON BIGGS, residing at Liverpool, in the county of Lancaster, in the Kingdom of England, have invented a new and useful Centrifugal Washing and Drying Machine, (for which I have obtained Letters Patent in Great Britain, No. 1,336, dated April 4, 1878,) of which the following is a specification.

Salt hitherto has never been dried commer' cially with centrifugal machines on account of its corrosive nature, corroding all cheap metallic substances that it comes in contact with, thus not merely destroying the centrifugal machine, but coloring and injuring the salt and brine operated upon. Now I get over this corrosive action by coating the iron in any of the well-known ways with a closely-adherin g film of magnetic oxide.

This machine or apparatus is designed more particularly for use in connection with other machinery for carrying out acontinuous process, for which application for Letters Patent was filed by me on the 13th day of February, 1879.

The coating of oxide may be applied in any suitable manner-for example, by first giving the metal a coating of any suitable adhesive material insoluble in water and applying the oxide thereto, or by giving the metal a thin film or coating of a readily-fusible metal and applying the oxide while the coating is in a fluid condition, or by dissolving the oxide in either of its various solvents and applying the liquid composition thus produced to the metal.

Figure 1 is a vertical section, and Fig. 2 a plan, of my centrifugal machine for both throwin g off the surplus brine from salt and for washing it. It is made of iron, the wire-gauze and other parts exposed to the salt being coated with magnetic oxide, and is preferably placed vertically, and based on strong masonry and concrete, with a passage beneath. It may, however, be placed in any suitable position and employed for drying and washing various styles of salt, including film-made salt produced from heated cylinders, fiat or other surfaces.

The drum A has its sides covered with very fine gauze or canvas supported by suitable bands or rings, or by an outer perforated casing. Within the gauze drum there is an inner (No model.) Patented in England April 4, 1878.

drum, B, having on its exterior a long screwblade, I), which all but touches the gauze 5 or it may have separate scrapers in one or more places on the drum, or' a long revolving screw, preferably on an axis parallel with the axis of the drum. The drums are mounted on a central shaft, U, and sleeve V, and move at a differential speed in such way that when salt is admitted at one end of the drum (in this case the top) it is scraped to the other end by the differential movement of the screw or scrapers within.

I sometimes deliver the salt onto a somewhat flattened radiating or rigid cone, 0, at the top of B; but I prefer to spread it out more evenly round the gauze drum by using a spout secured to the top of B, which is filled near the center, and which delivers the salt onto the gauze at a given depth a little in front of the first lap of the screw. This latter works it down by degrees to the discharge end of the drum, where it falls into the salt-chamber E. At the lower ends of the central shafts there are suitable driving-wheels, preferably conical friction-Wheels F G, which rest upon the sloping face of a cone, H, which are driven by a direct-acting three-cylindered or other suitable engine. The difference of the pitch of F and G regulates the differential speed of the upper drums,which are carried-drum Aby the sleeve V and drum B by the spindle U. The two drums A and B are placed in an outer casing, J, which I sometimes connect with the condenser or flue underneath to carry off the waste vapor. There is a passage, K, beneath to get at the engine and wheels.

Above the salt-chamber E there are two compartments, L M, separated by the sloping rings. The upper one, L, catches the brine thrown off from the first passage of the salt, and this is pumped or run back again into one of the pans for further evaporation, or otherwise treated. The second compartment, M, catches the brine passed through the salt for cleansing it from deliquescents, and communicates with a tank or drain.

N is the pipe and funnel by which a small quantity of fully-saturated brine is. admitted through the hollow part of the central shaft to the interior of the drum for this purpose. Pipe N carries the driving-spindle U, securely fixed in a socket on its end.

B and S are two plates placed across the inner drum, B, forming a compartment, T, into which the saturated brine falls from pipe N before passing through the salt and gauze drum.

Pipes for steam or water placed inside J are provided for cleaning the gauze externally, and I sometimes provide an additional pipe or pipes internally for washing or steaming the whole of the drum to free the gauze from obstruction, and for the same end occasionally employ brushes in the periphery of the screws 11.

Y is a discharging-elevator, (not shown in Fig. 1,) which may or may not be used.

I claim as my invention- 1. As a new article of manufacture, a centrifugal machine for cleaning and drying salt and other corrosive chemicals, in which the gauze and scrapers, and preferably the whole of the iron portions, are coated with magnetic oxide of iron.

2. In a centrifugal machine for cleaning or drying granular materials, the combination of an inner drum, B, the screw or scrapers b, and the outer cylinder, A, divided horizontally into compartments, substantially as described.

3. In a centrifugal cleaning or drying machine, the combination of the inner drum, B, with chamber T, supplied with saturated solution or other fluid for washing, said chamber being placed at such a height from the top as to allow the surplus moisture to escape before the material operated on comes opposite the said chamber '1.

4. In a centrifugal drying or cleaning ma chine, the combination of drum B, divided by horizontal partitions R and S, and the annular chambers L M, with inclined bottoms, so placed that one shall receive the surplus fluid from the material operated on, and the second the washings from chamber '1.

5. The funnel and hollow shaft N, perforated just below the partition It, and carrying the spindle U, securely fixed in its end, substantially as described.

JOHN HOWARD WORTHINGTON BIGGS.

Witnesses:

WM. P. THOMPSON, J OHN O. O'BRIEN. 

